The Advanced Television Systems Committee (ATSC) A/153 Mobile Handheld (M/H) standard is a terrestrial broadcast standard in North America for an in-band mobile TV service capable of providing terrestrial mobile digital television (MDTV) broadcast services simultaneously by inserting/transmitting a main service stream for an existing stationary DTV and a time-division mobile stream within a single RF 6 megahertz (MHz) channel. Here, the MDTV services utilize part of a bandwidth of 19.39 megabits per second (Mbps), which is an ATSC data transmission rate, and Internet Protocol (IP) datagram-based transmission technology, thereby providing mobile/portable TV viewers with broadcast services.
In detail, an entire broadcast frame of about 19.39 Mbps is transmitted via time division with an ATSC main broadcast stream moving picture experts group-2 transport stream (MPEG-2 TS) packet and an MDTV mobile stream packet (IP datagram), making simultaneous provision of two broadcast services possible, in an independent manner. A plurality of methods are available for providing a three-dimensional television (3DTV) service in such broadcast environments, for example, transmitting a stream of a main view image needed to compose a stereoscopic image, which is used for a stationary two-dimensional (2D) service, and a stream of a additional view image used to compose a 3D image along with the main view image as independent streams to an MPEG-2 TS packet.
Although the main view image stream is transmitted through an ATSC main broadcast stream to secure reverse compatibility with an existing stationary 2D broadcast, this method involves allocation of an additional band for transmission the additional view image stream. Due to the allocation of an additional band, reducing an amount of data transmitted for individual 2D screen information is necessary, resulting in deterioration of an existing 2D broadcast service.
To resolve such an issue, stationary and mobile hybrid 3DTV technology enabling transmission of a additional view image using a 2D mobile service stream instead of separately transmitting the additional view image for composing a 3D image is suggested. The stationary and mobile hybrid 3DTV technology has an advantage of providing a 3DTV service without allocation of an additional bandwidth for transmission of a additional view image. Here, in a stationary and mobile hybrid 3DTV, an ATSC main broadcast stream for a stationary broadcast uses an MPEG-2 system timing model based on a presentation timestamp/program clock reference (PTS/PCR) for video/audio synchronization, while an MDTV service stream for a mobile broadcast uses a timing model based on a real-time transport protocol (RTP) timestamp for video/audio synchronization.
In a conventional method, since an ATSC main broadcast standard and an MDTV broadcast standard have different video/audio synchronization modes, synchronizing an image stream of a left image and an image stream of a right image is difficult. Thus, there is need for a method of interpreting common presentation time information between a timing model based on a PTS/PCR and a timing model based on an RTP timestamp for synchronization of left and right images of the stationary and mobile hybrid 3DTV.